New Research Linking Ice Loss, Snow Loss, and Extreme Weather

December 9, 2013

Above, Dr. Jennifer Francis of Rutgers, and Dr. Jeff Masters of Weather Underground and the Weather Channel, on jetstream changes that may be responsible for changes in extreme weather events in the temperate zones.

Sea Ice cover, June, July, August, in red. Spring snow cover, May/June, in blue.“Since the 1980s, Arctic sea ice extent (SIE) has declined at a rate of about 8% per decade during September5, reaching a new record minimum in 2012. The area of summer sea-ice loss would cover over 40% of the contiguous United States6 . Snow-cover extent (SCE) on high-latitude, Northern Hemisphere land areas has also diminished during early summer. The rate of SCE loss during June from 1979 to 2011 of 17.8% per decade is even faster than the loss rate of Arctic SIE (ref. 7). “

Dr. Francis has a new paper just out reinforcing the sea ice connection with information about declining spring snow cover as well.

Abstract:

The past decade has seen an exceptional number of unprecedented summer extreme weather events in northern mid-latitudes, along with record declines in both summer Arctic sea ice and snow cover on high-latitude land. The underlying mechanisms that link the shrinking cryosphere with summer extreme weather, however, remain unclear.

Here, we combine satellite observations of early summer snow cover and summer sea-ice extent with atmospheric reanalysis data to demonstrate associations between summer weather patterns in mid-latitudes and losses of snow and sea ice.Results suggest that the atmospheric circulation responds differently to changes in the ice and snow extents, with a stronger response to sea-ice loss, even though its reduction is half as large as that for the snow cover. Atmospheric changesassociated with the combined snow/ice reductions reveal 0 widespread upper-level height increases, weaker upper-level zonal winds at high latitudes, a more amplified upper-level pattern, and a general northward shift in the jet stream.

More frequent extreme summer heat events over mid-latitude continents are linked with reduced sea ice and snow through these circulation changes.

A new study for the first time found links between the rapid loss of snow and sea ice cover in the Arctic and a recent spate of exceptional extreme heat events in North America, Europe, and Asia. The study adds to the evidence showing that the free-fall in summer sea ice extent and even sharper decline in spring snow cover in the Northern Hemisphere is reverberating throughout the atmosphere, making extreme events more likely to occur. –

There is virtually no controversy among climate scientists and meteorologists that massive changes have occurred in the Arctic environment during the past three decades, and that those changes are largely due to manmade greenhouse gas emissions.

Since the 1980s, Arctic sea ice extent has dropped at a rate of about 8 percent per decade during September, which is when the sea ice cover reaches its annual minimum. Arecord minimum was set in 2012. For a size comparison, consider that the area of summer sea ice lost since the 1980s would cover about 40 percent of the continental U.S., the study said.

Spring snow cover extent loss during June has dropped even more precipitously than sea ice cover, the study found, at a rate of about 18 percent per decade since 1979.

The case for a connection between Arctic warming and summertime extreme weather events rests on the Arctic’s crucial role as a pacesetter and shapemaker of the jet stream, the powerful ribbon of upper level winds that steer weather systems from west to east across the Northern Hemisphere.

Because the temperature contrast between the frigid Arctic and the milder mid-latitudes is what drives the powerful jet stream winds that guide weather systems, what happens in the Arctic is bound to have some sort of influence on the world’s weather. –

The new study, along with other previously published research, showed that the decline in sea ice and snow cover has slowed the west-to-easterly component of the jet stream, thereby enhancing the north-to-south waviness of the jet, which leads to the creation of more stagnant or “blocked” weather patterns. In addition, the new study found an association between sea ice and snow cover decline and a northward shift in the jet stream, which allows more warm air to move into the U.S. and Europe during the summer.

Paradoxically, other studies, including work by the same team of researchers, has shown that Arctic warming can actually enhance cold weather extremes in the U.S. and Europe during the winter.

Jennifer Francis, a meteorologist at Rutgers University, co-author of the new study, and the most prominent proponent of the hypothesis that Arctic warming is leading to more extreme weather events, told Climate Central that this study adds further evidence to the growing body of research supporting her team’s conclusions.

“While an observational study cannot pin down the mechanistic cause of the response, our results show a strong relationship between ice and snow losses during summer with heat waves in mid-latitude continents where billions of people are affected,” Francis said in an email conversation.

The cause/effect between arctic change and jetstream is not settled, pound on the table science. Below, an exchange between Dr. Francis and Dr. Kevin Trenberth, a leading researcher at the National Center for Atmospheric Research. Dr. Trenberth is not yet ready to sign on with the theory, but agrees that extreme weather events are increasing, and that we are seeing a “new normal” in climate.

Freedman again:

Judah Cohen, lead seasonal weather forecaster at AER, a weather and climate consulting firm, said the possibility that Arctic climate change is leading to more extreme weather patterns has initiated a flurry of new studies. “I can tell you that I am busier now reviewing journal papers than I have ever been in my career and they are all on sea ice” he said in an email. “I think this will be a dominant area of research and discourse for years to come.”

For her part, Francis is continuing to keep a wary eye on the weather map, convinced that the evidence for Arctic-induced weather extremes will continue to mount.

“As we continue to emit ever-increasing amounts of greenhouse gases into the atmosphere and as the Arctic continues to warm faster than mid-latitudes, we will see the case for the linkage strengthen,” Francis said. “I expect that with every year we will see a clearer response of weather patterns in all four seasons, and new modeling experiments will help elucidate the links in the chain, as well.”

I am at the American Geophysical Union meeting this week, and will be seeing and interview Dr. Francis, Dr. Masters and Dr. Trenberth, among others. Will have more updates and videos in coming weeks.

Doobious – eponymous. Water vapor is a greenhouse gas, i.e., it is a positive feedback. Do this little experiment. Go out on a clear, dry night, in the desert and on a cloudy, humid night. Observe how quickly the desert cools at night. It’s because water vapor reflects heat back to earth. It’s ridiculously easy to find references to water vapor as a greenhouse gas. Yet you inquire as if it is some mysterious conspiracy. Doobie, you are laying stinkers left and right. Your magical thermodynamics of geothermal is a stunning example. If the core of the earth is a heat source, the earth will always be endothermic at equilibrium. It’s area is a closed sphere. The only place for the energy to escape is the surface. No matter what the temperature of the surface or why, the core will be hotter. It’s like a furnace in your house. With the furnace on all the time, on a cold day outside, it’s just a cozy 76F inside. When it’s 100F outside, it’s 136F inside. The furnace is always endothermic. It’s not going to absorb heat at equilibrium. You seem to want us to explain what you have not learned or cannot comprehend. We get it. You don’t. You have already thoroughly discredited yourself as a serious thinker. A lot of bloggers are just too embarrassed to reply to your comments out of kindness. You have now attained omnologos status as a denier of the ridiculous. You had me going there for a while. A couple of people thought you were serious. Not anymore. I can read chapter and verse about your mistakes. It’s one thing to make a minor error. It’s another to completely fail to understand concepts and be unaware of easily available, well supported evidence.

So I take it that you too do not know of a study supporting the 2.5-5X multiplier of the Models. I cannot find one.

As I said: Both sides agree to the 1C rise for a doubling of CO2. Both sides agree that 1C temp rise should incite more water vapor. Both sides agree that water vapor is a yet more powerful GHG than CO2. The issue is: what becomes of this water vapor? If it all remains as a gas in the atmosphere it should incite more heating as in the Models. But no one knows how it might impact cloud formation. That’s the rub. And a 2% change in cloud cover is a BFD in either direction.

It seems reasonable to assume that at least some of the incited water vapor increase would remain gaseous and therefore contribute a positive feedback to additional atmospheric heating (as in the Models).

However, it similarly seems reasonable to assume that at least some of the incited water vapor increase would form additional cloud cover and therefore contribute a negative feedback to atmospheric cooling.

The question is: which one wins the battle. So far, we simply do not know.

This is the crucial question that intellectuals such as yourself are properly focused on.

Because we don’t know how to model cloud formation the modelers have heretofore assumed that it all remains gaseous. But obviously it all does not. That is the primary reason that the Models have tended to overstate the heating. And why the IPCC keeps lowering their estimates.

But for all we know, increased clouds win and the net of the whole feedback mechanism is negative (such that a doubling of CO2 would incite less than 1C of warming). And so far, this appears to be true.

I’m sure that you too have been locked onto this critical issue which remains unsettled.

Oh…and I forgot to mention: It appears that the Earth has turned to corner on temperature and that we are now, for none-anthropogenic reason, headed for cooling. As I’m sure you know, that’s potentially a big problem.